Over the past few weeks, there has been a growing spot on my driveway where I drive my car into the garage. The spot is made up of a very fine black powdery dust.

Right where this spot is located, there is a small bump as the wheels enter the garage. The location of this spot does not line up with anything I can think of that would be dropping the dust. I cleaned it up 1 week ago and as you can see from the pictures, it is back.

It is too far towards the middle of the car to be brake dust. The only thing that I see that lines up with the spot is the driver side muffler, which I have checked and see no leaks.

Any ideas what the source of this dust might be.

Hopefully you are doing that leaving the garage, and not going into it.

It looks like carbon deposits from the muffler -- ??? Not sure, thats a tough one.

That'* not a burn-out mark, its dust.

I have checked the entire exhust line and there are no leaks, so I don't think its carbon dust. The spot does not line-up with the exhaust tips, so it can't be coming from there.

That is a strange one. Any indication that brake dust could be collecting on the engine cradle, and then get knocked off as it goes over that bump? It does seem to be a lot for brake dust, though. How about the rubber donuts that hold the exhaust system?

Thinking about this more, I remembered that this spot lines up with the fly wheel dust cover. Could that be the source and if so, do I have a problem?

I did check the rubber supports for the exhaust and all seem OK. I will look closer for brake dust accumulation, but I agree that this is probably too much to be brake dust.

It could help knowing when it leaves the dust. Is it going into the garage, or out? Front wheels or back wheels? Maybe put some clean cardboard down, drive into the garage until the front wheels go up the bump, then stop. If the dust is there, then - check what may be right above it. If not...try again with the rear wheels? Do the same while backing out if nothing shows up.

I could be brake dust... Before I switched to cermanic pads I would get nasty spots in my driveway when I would wash the car once a week. But that dust had the help of water moving it.

Ed

I am pretty sure the dust falls when I am going out of the garage. Just by the way the dust drops look on the concrete, you can tell that they are falling on my way out.

I will try the cardboard and see if I can narrow it down.